Naphtha is a general term describing a group of volatile, flammable, petroleum derived hydrocarbon solvents that include benzine, lighter fluid, and certain grades of gasoline, but specifically exclude the heavier and less volatile kerosene fraction of petroleum distillation. The term encompasses a range of light petroleum distillates of varying composition and volatility, all sharing the common characteristics of rapid evaporation at room temperature, strong solvent action on oils, greases, waxes, and certain adhesives, and a characteristic petroleum odour.
In photographic practice, naphtha based solvents have found application as cleaning agents for removing grease, oil, adhesive residues, and other organic contaminants from camera equipment, lens elements, darkroom tools, and other photographic hardware. The solvent properties of naphtha make it effective at dissolving and lifting oily deposits from metal and glass surfaces without leaving a significant residue after evaporation, provided it is applied carefully and sparingly. It has also been used historically in certain photographic mounting and finishing processes, and as a solvent component in some specialised photographic chemistry formulations.
The handling of naphtha in a photographic context demands careful attention to health and safety considerations. As a volatile petroleum distillate, naphtha is highly flammable and its vapours can form explosive mixtures with air at relatively low concentrations, making adequate ventilation and the elimination of ignition sources essential precautions when working with it. Prolonged or repeated skin contact can cause dermatitis and remove natural skin oils, and inhalation of naphtha vapours in significant concentrations can cause dizziness, headache, and respiratory irritation. The use of appropriate personal protective equipment including solvent resistant gloves and eye protection is advisable when handling naphtha, and the material should be stored in tightly sealed containers away from heat sources, open flames, and other ignition hazards in accordance with the relevant safety data sheet guidance.
In modern photographic and optical cleaning practice, naphtha based solvents have been largely supplemented or replaced by safer and more purpose formulated cleaning products including isopropyl alcohol, dedicated optical cleaning fluids, and specialised lens cleaning solutions that offer effective cleaning action with lower flammability, toxicity, and environmental impact than traditional petroleum naphtha products.